aseos2004 Posted December 27, 2008 Report Share Posted December 27, 2008 I needed to know what is the maximum tire width and size I can go with the stock 18s. I've gotten conflicting answers from tire centers. Naturally I'm turning to the pros. Link to comment Share on other sites More sharing options...
abe Posted December 27, 2008 Report Share Posted December 27, 2008 Most tire manufacturer web sites will list min-max rim width for their tires. When I was looking I decided a 255 would be about it with the stock 18x8.5. Im sure that isnt the definitive answer though. Link to comment Share on other sites More sharing options...
zdle Posted December 27, 2008 Report Share Posted December 27, 2008 I needed to know what is the maximum tire width and size I can go with the stock 18s. I've gotten conflicting answers from tire centers. Naturally I'm turning to the pros. Great pictures , and I really like the stuff you have done to your car, good spoiler , what is it ? , and the billet gas cap cover looks great on the orange cars .........very nice..........not over cooked ...................ZDS Link to comment Share on other sites More sharing options...
68fastback Posted December 27, 2008 Report Share Posted December 27, 2008 I needed to know what is the maximum tire width and size I can go with the stock 18s. I've gotten conflicting answers from tire centers. Naturally I'm turning to the pros. The actual tread width, as a general rule, should not exceed the actual rim width. If the tread is wider, handling/turn-in will get progressively looser/less-responsive but straight-line traction might improve as long as tread lays flat on the road at target pressures. If the tread is narrower, handling/turn-in will get progressively more responsive but straight-line traction may be reduced. Sidewall height also affects handling/turn-in responsiveness. Don't go by the manufacturer's stated width since the exact same nominal size tire (e.g. 255mm) can vary substantially in actual tread and section widths. The actual tread width and sidewall height also interacts with damper/strut valving and spring rates. In general, taller sidewalls are more 'forgiving' but delay turn-in responsiveness, so if you're planning higher-rate springs and higher damping shocks, it makes sense to go to wider wheels with tires a bit narrower than the wider wheel to better take advantage of the benefits of the improved springs/shocks better overall responsiveness, whereas tires wider than the wheels might not only give back much/all of the suspension benefits but might make for less control at the limits such that predictability is reduced. The above are just some concepts to consider based on your goals and how they might affect what tire/wheel sizes might fit and other eperiences with them. In general, shorter sidewalls will increase turn-in and responsiveness 'feel' but may actually negatively impact overall handling because the higher rebound frequency (less compliance at safe tire pressures) of shorter sidewalls may not be a good match for the high unsprung weight of the live rear axle. If the best road-course handling with a good street ride is your goal, I'd stick with the widest 18" wheels that will clear with a slightly numerically lower aspect ratio such that the rolling radius remains unchanged. For example, going from a 255/40/18 to a 285/35/18 (again, will depend on brand) will benefit handling whether with stock springs or with slightly stiffer springs/dampers and will still be compliant and forgiving on the street. You can see there's no one answer -- it depends on your goals and planned use ...just be sure to avoid the temptation to go with tires with actual tread widths wider than the wheels since that can make for predictability problems. -Dan Link to comment Share on other sites More sharing options...
LuLu Posted December 27, 2008 Report Share Posted December 27, 2008 The actual tread width, as a general rule, should not exceed the actual rim width. If the tread is wider, handling/turn-in will get progressively looser/less-responsive but straight-line traction might improve as long as tread lays flat on the road at target pressures. If the tread is narrower, handling/turn-in will get progressively more responsive but straight-line traction may be reduced. Sidewall height also affects handling/turn-in responsiveness. Don't go by the manufacturer's stated width since the exact same nominal size tire (e.g. 255mm) can vary substantially in actual tread and section widths. The actual tread width and sidewall height also interacts with damper/strut valving and spring rates. In general, taller sidewalls are more 'forgiving' but delay turn-in responsiveness, so if you're planning higher-rate springs and higher damping shocks, it makes sense to go to wider wheels with tires a bit narrower than the wider wheel to better take advantage of the benefits of the improved springs/shocks better overall responsiveness, whereas tires wider than the wheels might not only give back much/all of the suspension benefits but might make for less control at the limits such that predictability is reduced. The above are just some concepts to consider based on your goals and how they might affect what tire/wheel sizes might fit and other eperiences with them. In general, shorter sidewalls will increase turn-in and responsiveness 'feel' but may actually negatively impact overall handling because the higher rebound frequency (less compliance at safe tire pressures) of shorter sidewalls may not be a good match for the high unsprung weight of the live rear axle. If the best road-course handling with a good street ride is your goal, I'd stick with the widest 18" wheels that will clear with a slightly numerically lower aspect ratio such that the rolling radius remains unchanged. For example, going from a 255/40/18 to a 285/35/18 (again, will depend on brand) will benefit handling whether with stock springs or with slightly stiffer springs/dampers and will still be compliant and forgiving on the street. You can see there's no one answer -- it depends on your goals and planned use ...just be sure to avoid the temptation to go with tires with actual tread widths wider than the wheels since that can make for predictability problems. -Dan Better said...255/45-18 Link to comment Share on other sites More sharing options...
68fastback Posted December 27, 2008 Report Share Posted December 27, 2008 Better said...255/45-18 Better than what? ...a cogent answer that might actually help someone understand more about their choices and tradeoffs? Better ...as in a dogmatically-simplistic take-it-or-leave-it-here's-*the*-answer? Simplistic answers can seem satisfying but ultimately have their perils -- like being good only for an unstated set of assumptions. This isn't law-enforcement, it's an enthusiast site for mutual assistance, imo. But thanks for your "better" answer Link to comment Share on other sites More sharing options...
LuLu Posted December 27, 2008 Report Share Posted December 27, 2008 I needed to know what is the maximum tire width and size I can go with the stock 18s. I've gotten conflicting answers from tire centers. Naturally I'm turning to the pros. The gentleman asked for what is (has been) tried and shows true. 'Nuff said. If aseos2004 had asked for more 411, such as suspension function and dynamics, another answer may have been offered. He did not ask. Better than what? ...a cogent answer that might actually help someone understand more about their choices and tradeoffs? Better ...as in a dogmatically-simplistic take-it-or-leave-it-here's-*the*-answer? Simplistic answers can seem satisfying but ultimately have their perils -- like being good only for an unstated set of assumptions. This isn't law-enforcement, it's an enthusiast site for mutual assistance, imo. But thanks for your "better" answer No...This site is not about law enforcement, but it is meant to be as helpful. Direct questions earn direct answers, yes? But, let's say they do not? If that is the case, why didn't you mention tire/rubber compound and PSI in your reply? Would have been as helpful, don't you agree? Link to comment Share on other sites More sharing options...
68fastback Posted December 27, 2008 Report Share Posted December 27, 2008 The gentleman asked for what is (has been) tried and shows true. 'Nuff said. If he asked for more, such as suspension function and dynamics, another answer may have been offered. He did not ask. So then respond to him. Why are you quoting my thoughtful response and calling yours "better?" I perceive that as a veiled attack. Grow up and lose the attitude, please. No context of how he planned to use the car was stated, so I decided to provide a response such that *he* could decide if/what may apply to *his* situation. You don't like that? Tough. I'll determine what I say to others, not you. As I've said before, if you don't like my posts just put me on ignore. Nuf said. Link to comment Share on other sites More sharing options...
LuLu Posted December 29, 2008 Report Share Posted December 29, 2008 What. Ever... Link to comment Share on other sites More sharing options...
7ONE7 Posted December 31, 2008 Report Share Posted December 31, 2008 Yup.... Link to comment Share on other sites More sharing options...
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